Is Coronary Angiogram Useful to Predict the Onset of Acute Myocardial Infarction

We studied 37 patients to investigate whether the findings of the coronary angiograms can predict the onset of acute myocardial infarction. A second coronary angiogram was performed after the onset of acute myocardial infarction in 37 patients with organic coronary artery disease who had received medical treatment and had previously undergone cardiac catheterization. The interval between the two angiograms was 38±31 months.At the second coronary angiogram, 18 (49%) of the 37 infarct-related arteries showed no or only minimal irregular lesions, and 28 (76%) showed less than 70% stenoses. At the second angiogram after infarction, however, most cases (81-100%) showed lesions with more than 90% stenoses in infarct-related arteries.We also investigated 43 patients who underwent repeated coronary angiograms due to unstable angina with an interval of 49±37 months. In contrast to myocardial infarction, 25 (58%) of the 43 lesions which were responsible for unstable angina at the second angiogram had already had more than 70% stenoses at the first examination.In addition, among 46 patients with vasospastic angina, repeated angiograms at an interval of 46±36 months revealed that the progression of atherosclerotic stenosis occurs more frequently in coronary arteries with vasospasm than in those without it.We conclude that the pathogenesis causing acute myocardial infarction differs from that of unstable angina and that the future onset of myocardial infarction is not predictable from a coronary angiogram. In addition, coronary vasospasm may contribute to the progression of coronary atherosclerotic lesions.